Abstract: A light waveguide switch which has a base member with a flat surface sub-divided by a longitudinally extending channel, a flat plate of a constant thickness being pre-cut to form a tongue and a carrier member, waveguides secured to the tongue and carrier member to be in alignment when the tongue engages the flat surface of the carrier member and an adjustable stop for defining a second switching position characterized by the adjustable stop being formed by a resilient arm secured on the carrier member to extend across the tongue adjacent the free end thereof, and having a projection forming a point contact second stop with the tongue and having the free end of the arm being connected to the carrier member by an adjustment screw so that a projection on the arm forms an adjustable stop to determine the second position.